What is the brand name for Sulfamethoxazole / Trimethoprim?
The most common brand name for Sulfamethoxazole / Trimethoprim is Bactrim / Septra.
PTCE Top 200 · #128
Sulfamethoxazole / Trimethoprim
Bactrim / Septra
Sulfamethoxazole / Trimethoprim is the generic name for the brand-name drug Bactrim. It is a sulfonamide antibiotic combination used to treat UTI, MRSA, PCP. On the PTCE Top 200 drug list, Sulfamethoxazole / Trimethoprim ranks #128 and is one of the most frequently tested infectious disease medications — commonly quizzed on its brand–generic pair, drug class, and key side effects.
| Generic name | Sulfamethoxazole / Trimethoprim |
|---|---|
| Brand name(s) | Bactrim / Septra |
| Drug class | Sulfonamide antibiotic combination |
| Class group | Infectious Disease |
| Common use | UTI, MRSA, PCP |
| DEA schedule | Unscheduled |
| Availability | Prescription only (Rx) |
What is Sulfamethoxazole / Trimethoprim used for?
Treatment of susceptible infections (commonly UTIs); treatment/prophylaxis of Pneumocystis jirovecii pneumonia (PCP); other susceptible bacterial infections.
What drug class is Sulfamethoxazole / Trimethoprim?
Sulfamethoxazole / Trimethoprim is a Sulfonamide antibiotic combination in the Infectious Disease group. Knowing the class is the fastest way to predict its uses, side effects, and the brand↔generic pairs the PTCE tests.
Common side effects of Sulfamethoxazole / Trimethoprim
- arrow_rightNausea
- arrow_rightVomiting
- arrow_rightRash
- arrow_rightPhotosensitivity
- arrow_rightLoss of appetite
- arrow_rightHyperkalemia
Major interactions
- arrow_rightWarfarin → increased INR/bleeding risk
- arrow_rightACEi/ARB/spironolactone → hyperkalemia risk
- arrow_rightMethotrexate → increased bone marrow suppression/toxicity
- arrow_rightDofetilide → contraindicated (risk of serious arrhythmias)
- arrow_rightPhenytoin → increased levels/toxicity
Is Sulfamethoxazole / Trimethoprim a controlled substance?
No. Sulfamethoxazole / Trimethoprim is not a federally controlled substance (it is unscheduled by the DEA).
How to remember Sulfamethoxazole / Trimethoprim (PTCE mnemonic)
BAC-trim BATtles UTI/MRSA — TMP-SMX = 'Two in one' sulfa. Rash → Stevens-Johnson, ↑K+, ↑INR with warfarin, ↑MTX toxicity; sulfa allergy; no late pregnancy.
lightbulb
PTCE exam tip
TMP/SMX is the sulfa-allergy screening classic — it also raises warfarin's INR and potassium levels, two interaction favorites.
Sulfamethoxazole / Trimethoprim FAQ
What is Sulfamethoxazole / Trimethoprim used for?
Sulfamethoxazole / Trimethoprim is used to treat UTI, MRSA, PCP. Treatment of susceptible infections (commonly UTIs); treatment/prophylaxis of Pneumocystis jirovecii pneumonia (PCP); other susceptible bacterial infections.
What drug class is Sulfamethoxazole / Trimethoprim?
Sulfamethoxazole / Trimethoprim is a Sulfonamide antibiotic combination (Infectious Disease group).
Is Sulfamethoxazole / Trimethoprim a controlled substance?
No. Sulfamethoxazole / Trimethoprim is not a federally controlled substance (it is unscheduled by the DEA).
Related drugs in the Infectious Disease group
Drill Sulfamethoxazole / Trimethoprim the way the PTCE asks it
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Last reviewed June 25, 2026. Educational use only — not medical advice. Verify clinical specifics with your pharmacist or a current label source such as DailyMed. RxReflex is not affiliated with or endorsed by the Pharmacy Technician Certification Board (PTCB).